test/zdtmp: add a test to C/R shared memory file descriptors

Any shared memory region can be openned via /proc/self/map_files.

Signed-off-by: Andrei Vagin <avagin@gmail.com>

test/zdtm/static/Makefile

@@ -224,6 +224,8 @@ TST_NOFILE	:=				\
 		memfd01				\
 		memfd02				\
 		memfd03				\
+		shmemfd				\
+		shmemfd-priv			\
 #		jobctl00			\
 
 ifneq ($(ARCH),arm)

test/zdtm/static/shmemfd-priv.c

@@ -0,0 +1,84 @@
+#include <unistd.h>
+#include <stdio.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <sys/vfs.h>
+#include <fcntl.h>
+
+#include "zdtmtst.h"
+
+const char *test_doc	= "Test C/R of shared memory file descriptors";
+const char *test_author	= "Andrei Vagin <avagin@gmail.com>";
+
+#define err(exitcode, msg, ...) ({ pr_perror(msg, ##__VA_ARGS__); exit(exitcode); })
+
+int main(int argc, char *argv[])
+{
+	void *addr, *priv_addr, *addr2;
+	char path[4096];
+	int fd;
+
+	test_init(argc, argv);
+
+	addr = mmap(NULL, 5 * PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0);
+	if (addr == MAP_FAILED) {
+		pr_perror("mmap");
+		return 1;
+	}
+
+	*(int *) addr = 1;
+	*(int *) (addr + PAGE_SIZE) = 11;
+	*(int *) (addr +  2 * PAGE_SIZE) = 111;
+
+	snprintf(path, sizeof(path), "/proc/self/map_files/%lx-%lx",
+					(long)addr, (long)addr + 5 * PAGE_SIZE);
+	fd = open(path, O_RDWR | O_LARGEFILE);
+	if (fd < 0)
+		err(1, "Can't open %s", path);
+
+	priv_addr = mmap(NULL, 5 * PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_FILE | MAP_PRIVATE, fd, PAGE_SIZE);
+	if (priv_addr == MAP_FAILED) {
+		pr_perror("mmap");
+		return 1;
+	}
+
+	addr2 = mmap(NULL, 5 * PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_FILE | MAP_SHARED, fd, 2 * PAGE_SIZE);
+	if (addr2 == MAP_FAILED) {
+		pr_perror("mmap");
+		return 1;
+	}
+
+	*(int *) (priv_addr + PAGE_SIZE) = 22;
+
+	test_daemon();
+	test_waitsig();
+
+	if (*(int *) (priv_addr + PAGE_SIZE) != 22) {
+		fail("the second page of the private mapping is corrupted");
+		return 1;
+	}
+	if (*(int *) (priv_addr) != 11) {
+		fail("the first page of the private mapping is corrupted");
+		return 1;
+	}
+	if (*(int *) (addr2) != 111) {
+		fail("the first page of the second shared mapping is corrupted");
+		return 1;
+	}
+	*(int *) (addr2) = 333;
+	if (*(int *) (addr + 2 * PAGE_SIZE) != 333) {
+		fail("the first page of the second shared mapping isn't shared");
+		return 1;
+	}
+	*(int *) (addr + 3 * PAGE_SIZE) = 444;
+	if (*(int *) (priv_addr + 2 * PAGE_SIZE) != 444) {
+		fail("the third page of the private mapping is corrupted");
+		return 1;
+	}
+
+	pass();
+
+	return 0;
+}

test/zdtm/static/shmemfd-priv.desc

@@ -0,0 +1 @@
+{'flavor': 'h ns', 'flags': 'suid'}

test/zdtm/static/shmemfd.c

@@ -0,0 +1,107 @@
+#include <unistd.h>
+#include <stdio.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <sys/vfs.h>
+#include <fcntl.h>
+
+#include "zdtmtst.h"
+
+const char *test_doc	= "Test C/R of shared memory file descriptors";
+const char *test_author	= "Andrei Vagin <avagin@gmail.com>";
+
+#define err(exitcode, msg, ...) ({ pr_perror(msg, ##__VA_ARGS__); exit(exitcode); })
+
+int main(int argc, char *argv[])
+{
+	int fd, fl_flags1, fl_flags2, fd_flags1, fd_flags2;
+	struct statfs statfs1, statfs2;
+	off_t pos1, pos2;
+	char path[4096];
+	char buf[5];
+	void *addr;
+
+	test_init(argc, argv);
+
+	addr = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0);
+	if (addr == MAP_FAILED) {
+		pr_perror("mmap");
+		return 1;
+	}
+
+	snprintf(path, sizeof(path), "/proc/self/map_files/%lx-%lx",
+					(long)addr, (long)addr + PAGE_SIZE);
+	fd = open(path, O_RDWR | O_LARGEFILE);
+	if (fd < 0)
+		err(1, "Can't open %s", path);
+	ftruncate(fd, 0);
+	munmap(addr, PAGE_SIZE);
+
+	if (fcntl(fd, F_SETFL, O_APPEND) < 0)
+		err(1, "Can't get fl flags");
+
+	if ((fl_flags1 = fcntl(fd, F_GETFL)) == -1)
+		err(1, "Can't get fl flags");
+
+	if ((fd_flags1 = fcntl(fd, F_GETFD)) == -1)
+		err(1, "Can't get fd flags");
+
+	if (fstatfs(fd, &statfs1) < 0)
+		err(1, "statfs issue");
+
+	if (write(fd, "hello", 5) != 5)
+		err(1, "write error");
+
+	pos1 = 3;
+	if (lseek(fd, pos1, SEEK_SET) < 0)
+		err(1, "seek error");
+
+	test_daemon();
+	test_waitsig();
+
+	if ((fl_flags2 = fcntl(fd, F_GETFL)) == -1)
+		err(1, "Can't get fl flags");
+
+	if (fl_flags1 != fl_flags2) {
+		fail("fl flags differs %x %x", fl_flags1, fl_flags2);
+		return 1;
+	}
+
+	if ((fd_flags2 = fcntl(fd, F_GETFD)) == -1)
+		err(1, "Can't get fd flags");
+
+	if (fd_flags1 != fd_flags2) {
+		fail("fd flags differs");
+		return 1;
+	}
+
+	if (fstatfs(fd, &statfs2) < 0)
+		err(1, "statfs issue");
+
+	if (statfs1.f_type != statfs2.f_type) {
+		fail("statfs.f_type differs");
+		return 1;
+	}
+
+	pos2 = lseek(fd, 0, SEEK_CUR);
+	if (pos1 != pos2) {
+		fail("position differs");
+		return 1;
+	}
+
+	if (pread(fd, buf, sizeof(buf), 0) != sizeof(buf)) {
+		fail("read problem");
+		return 1;
+	}
+
+	if (memcmp(buf, "hello", sizeof(buf))) {
+		fail("content mismatch");
+		return 1;
+	}
+
+	pass();
+
+	return 0;
+}

test/zdtm/static/shmemfd.desc

@@ -0,0 +1 @@
+{'flavor': 'h ns', 'flags': 'suid'}